[3][4][5][6][7] Features include monitoring of the health status of the arrays, controlling identification through blinking the LEDs and managing of sound alarms, and specifying hot spare disks.
The bio/bioctl subsystem is deemed to be an important part in OpenBSD's advocacy for open hardware documentation, and the 3.8 release title and the titular song were dedicated to the topic — Hackers of the Lost RAID.
[9] In the commentary to the 3.8 release,[9] the developers express the irony of hardware RAID controllers' supposed purpose of providing reliability, through redundancy and repair, whereas in reality many vendors expect system administrators to install and depend on huge binary blobs in order to be assess volume health and service their disk arrays.
Specifically, OpenBSD is making a reference to the modus operandi of FreeBSD, where the documentation of the aac(4) driver for Adaptec specifically suggests enabling Linux compatibility layer in order to use the management utilities (where the documentation even fails to explain where exactly these utilities must be obtained from, or which versions would be compatible, evidently because the proprietary tools may have expired).
[18] For example, on OpenBSD since 4.2 release, the status of the drive sensors could be automatically monitored simply by starting sensorsd without any specific configuration being required.